Re: [PATCH RFC] virtio-blk: support per-device queue depth
From: Jason Wang <hidden>
Date: 2021-01-19 04:19:57
Also in:
virtualization
On 2021/1/18 上午11:58, Joseph Qi wrote:
module parameter 'virtblk_queue_depth' was firstly introduced for
testing/benchmarking purposes described in commit fc4324b4597c
("virtio-blk: base queue-depth on virtqueue ringsize or module param").
Since we have different virtio-blk devices which have different
capabilities, it requires that we support per-device queue depth instead
of per-module. So defaultly use vq free elements if module parameter
'virtblk_queue_depth' is not set.
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>Acked-by: Jason Wang <redacted>
quoted hunk ↗ jump to hunk
--- drivers/block/virtio_blk.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 145606d..f83a417 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c@@ -705,6 +705,7 @@ static int virtblk_probe(struct virtio_device *vdev) u32 v, blk_size, max_size, sg_elems, opt_io_size; u16 min_io_size; u8 physical_block_exp, alignment_offset; + unsigned int queue_depth; if (!vdev->config->get) { dev_err(&vdev->dev, "%s failure: config access disabled\n",@@ -755,17 +756,18 @@ static int virtblk_probe(struct virtio_device *vdev) goto out_free_vq; } - /* Default queue sizing is to fill the ring. */ - if (!virtblk_queue_depth) { - virtblk_queue_depth = vblk->vqs[0].vq->num_free; + if (likely(!virtblk_queue_depth)) { + queue_depth = vblk->vqs[0].vq->num_free; /* ... but without indirect descs, we use 2 descs per req */ if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC)) - virtblk_queue_depth /= 2; + queue_depth /= 2; + } else { + queue_depth = virtblk_queue_depth; } memset(&vblk->tag_set, 0, sizeof(vblk->tag_set)); vblk->tag_set.ops = &virtio_mq_ops; - vblk->tag_set.queue_depth = virtblk_queue_depth; + vblk->tag_set.queue_depth = queue_depth; vblk->tag_set.numa_node = NUMA_NO_NODE; vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; vblk->tag_set.cmd_size =